Surface modification of metal materials for high-performance electrocatalytic carbon dioxide reduction

Electrocatalytic CO₂ reduction reaction (CO₂RR) has attained great attention as it can transform the greenhouse gas CO₂ to value-added chemicals, such as carbon monoxide, formic acid, ethylene, ethanol, and n-propanol. However, the electrocatalytic performance of materials, especially the metal materials, toward the CO₂RR is still limited due to the complex reaction processes and broad product distribution. Very recently, surface modification of metal materials has emerged as an effective way to boost their electrocatalytic CO₂RR performance. Herein, recent advances in the surface modification of metal materials, which includes surface molecular functionalization, surface elemental doping, and surface plasma treatment, for CO₂RR are presented. The surface modification-induced variations of surface states and electrocatalytic performances of metal materials, together with the underlying mechanisms, are highlighted. It is believed that the development of surface modification could promote the rational design and preparation of advanced CO₂RR electrocatalysts toward practical applications.